Eventually Cesc Fabregas will sign for Barcelona, of that fact there is little doubt in my mind for the following reasons.
a) He's Catalan
b) He started his career at Barcelona
c) He'll never win a trophy at Arsenal (I can hear the Arsenal fans scrambling for their keyboards even now.)
However, it won't be for a few years yet given that in his position at Barcelona they have Xavi and Andres Iniesta hence he'd be pretty much restricted to the role of a squad player.